Ok, so I managed to cobble some of it together.
Where it seems to break is when you try to build out the new Force Powers to match those you have updated in the Force Abilities.xml.
When I copy say Move and rename all the MOVE keys to ENHANCE, it breaks when I try to add a Force specialization to a character.
Has anyone managed to make this work?
if you're copying an existing power or ability into DataCustom and then renaming the key, make sure you add a <Custom> tag with a value of "Added". The new powers you're creating might not be showing up in the data if you don't do that. That could cause problems if you create a specialization or power that expects those keys to be present.
Ok, I will try that.